Nitrous oxide when placed under a sufficient pressure will be in liquid form and is used for a variety of purposes, one of which is in high preformance vehicles such as racecars, boats or the like in order to achieve a sudden burst of power to the vehicle engine for a short period of time. The use of nitrous oxide for charging a vehicle engine is disclosed in U.S. Pat. No. 4,494,488 which is assigned to the same assignee as in the present invention. Although the use of bottles of liquid nitrous oxide in a racing vehicle or boat has proved successful in obtaining the desired results, it has presented a problem of satisfactory refilling such bottles at the site of the race or boat dock.
Heretofore, the smaller bottles which are placed in the vehicles and boats are filled with liquid nitrous oxide at an industrial supply house generally by several known procedures. One procedure involves filling the smaller bottles of nitrous oxide from a larger cylinder by connecting the two bottles with a conduit. The liquid nitrous oxide will flow from the larger cylinder to the smaller bottle by the pressure within the supply cylinder. However, to insure satisfactory transfer of the liquid nitrous oxide between the two containers and to prevent the liquid nitrous oxide from vaporizing when flowing from the larger cylinder to the smaller bottle which forms a back pressure in the bottle retarding the filling of the bottle, the bottle is cooled to a very low temperature by placing it in a freezer for several hours or by injecting a small quantity of the liquid nitrous oxide into the bottle, then releasing it from the bottle which upon vaporizing to the atmosphere will cool the bottle. Both of these known procedures result in increased costs due to the refrigeration unit required for cooling the bottle and cylinder and the loss of the nitrous oxide required for cooling the bottle since it is vented into the surrounding atmosphere. Another method of filling the bottles is by the use of a large pump which transfers the nitrous oxide from a large supply tank into the individual, preferably cooled bottles. However, the pump is relatively expensive, not portable and should be maintained in a cool state to prevent the nitrous oxide from vaporizing during transfer.
Another serious problem that occurs when filling a small bottle from a larger cylinder of nitrous oxide is that upon the pressure differential between the two containers becoming equalized approximately 20% of the nitrous oxide in the cylinder is unable to be transferred into smaller bottles. Furthermore, as the nitrous oxide in the larger cylinder becomes depleted, the amount of time required to fill the smaller bottles from the cylinder increases considerably due to equalization of the pressure.
Although it is desirable that the bottles be refilled at the racetrack, boatdock, or similar site, such locations usually provide a hot environment for the bottles and supply cylinders. These high temperatures result in the rapid vaporization of the liquid nitrous oxide during transfer with the resulting buildup of back pressure in the bottle preventing it from being satisfactory filled in a reasonable length of time. Also, it is possible to only partially empty the nitrous oxide from the supply cylinder.
During the heretofore pressure differential transfer of the liquid nitrous oxide from the cylinder into the smaller bottles, the cylinder and bottles are inverted in order to facilitate the transfer of the liquid nitrous oxide from the cylinder into smaller bottles. Although this increases the effectiveness of the transfer, it presents another problem in that contaminates within the bottle and cylinder, usually in the form of small particles of dirt or rust, will flow downwardly into the discharge nozzle or valve portion of the cylinder and into the bottle. These contaminates could cause a malfunction of the injection system on the vehicle. Furthermore, the equipment being used for effecting the transfer of the liquid nitrous oxide is difficult to use at the site of a race due to the lack of portability thereof.
Therefore, the need has existed for an improved system for filling bottles with liquid nitrous oxide from a larger supply cylinder when both the bottle and cylinder are at ambient temperature, and in which the system is completely portable enabling the same to be accomplished at a race site or other location remote from a usual industrial liquid nitrous oxide supply facility.